KR101901758B1 - organic light emitting diode device - Google Patents

Abstract

The present invention provides a liquid crystal display comprising: a first substrate including a plurality of sub pixel regions; A first electrode opposed to the plurality of sub pixel areas and disposed on each of the plurality of sub pixel areas and a second electrode facing the first electrode and covering the entirety of the plurality of sub pixel areas and made of a silver / magnesium alloy having a silver content greater than a magnesium content, And an organic light emitting layer disposed between the first electrode and the second electrode in each of the plurality of sub pixel regions; A first protective layer formed on the light emitting diode and covering the entire first substrate, the first protective layer being made of a first inorganic insulating material; And a second substrate disposed on the first passivation layer, wherein a refractive index of the first inorganic insulating material is greater than a refractive index of the second substrate.

Description

[0001] The present invention relates to an organic light emitting diode device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting diode device, and more particularly, to an organic light emitting diode device having a high aperture ratio and a high transmittance.

One of the new flat panel displays, Organic Light Emitting Diode Device (OELD Device), is self-emitting type, so it has better viewing angle and contrast ratio than liquid crystal display device and does not need backlight It is lightweight and thin, and is also advantageous in terms of power consumption. And it is able to drive DC low voltage, has fast response time and is all solid, so it is resistant to external impact, has wide temperature range, and is cheap in terms of manufacturing cost. Such an organic light emitting display device is also called an organic electroluminescent display device (OELD device).

Unlike a liquid crystal display device or a plasma display panel (PDP device), the organic light emitting diode device is a very simple process, so it can be said that all of the deposition and encapsulation devices are used.

Particularly, in the active matrix type, a voltage for controlling a current applied to a pixel is charged in a storage capacitor, and a voltage is maintained until a next frame signal is applied, Regardless of the number of wirings, a light emission state is maintained while a single screen is displayed, which will be described with reference to the drawings.

1 is a view showing one sub-pixel region of a conventional organic light emitting diode device.

1, a gate wiring GL, a data wiring DL and a power wiring PL are formed in the organic light emitting diode element so as to intersect with each other to define the sub pixel region SP, A switching thin film transistor Ts, a driving thin film transistor Td, a storage capacitor Cst, and a light emitting diode Del are formed on the substrate SP.

The switching thin film transistor Ts is connected to the gate wiring GL and the data wiring DL and the driving thin film transistor Td and the storage capacitor Cst are connected between the switching thin film transistor Ts and the power wiring PL. And the light emitting diode Del is connected to the driving thin film transistor Td.

When the switching thin film transistor Ts is turned on in response to a gate signal applied to the gate line GL, data on the data line DL is applied to the organic light emitting diode A signal is applied to the gate electrode of the driving thin film transistor Td and one electrode of the storage capacitor Cst through the switching thin film transistor Ts.

The driving thin film transistor Td is turned on in accordance with the data signal applied to the gate electrode so that a current proportional to the data signal is supplied from the power wiring PL to the light emitting diode Del through the driving thin film transistor Td And the light emitting diode Del emits light with a luminance proportional to the current flowing through the driving thin film transistor Td.

At this time, the storage capacitor Cst is charged with a voltage proportional to the data signal so that the voltage of the gate electrode of the driving thin film transistor Td is kept constant during one frame.

Therefore, the organic light emitting diode device can display a desired image by a gate signal and a data signal.

2, which is a cross-sectional view schematically showing a sub-pixel region of a conventional organic light emitting diode device, an organic light emitting diode device 1 includes a first substrate 10, a second substrate 10 facing the first substrate 10, And a light emitting diode (Del) is disposed between the first and second substrates (10, 20). A seal pattern 30 is formed on the edges of the first and second substrates 10 and 20 and the first and second substrates 10 and 20 are bonded together by the seal pattern 30 .

In more detail, a switching thin film transistor (Ts in FIG. 1), a driving thin film transistor Td, and a storage capacitor (Cst in FIG. 1) are formed on the first substrate 10 for each subpixel SP And a light emitting diode Del connected to each of the driving thin film transistors Td is formed. Although not shown in the drawing, the driving thin film transistor Td includes a gate electrode, a semiconductor layer, and a source electrode and a drain electrode.

The light emitting diode Del includes a first electrode 12 connected to the driving thin film transistor Td, a second electrode 16 facing the first electrode 12, 12, and 16, respectively.

The first electrode 12 is made of a conductive material having a relatively large work function to serve as an anode and the second electrode 16 is formed of a material having a relatively low work function value And is made of a small conductive material.

When a voltage is applied to the first and second electrodes 12 and 16, holes and electrons move from the first and second electrodes 12 and 16 to the organic light emitting layer 14, thereby emitting light from the organic light emitting layer 14.

The organic light emitting layer 14 is formed of an organic thin film pattern of red (R), green (G), and blue (B), and may have a multi-layer structure for improving luminous efficiency. For example, the organic light emitting layer 14 may include a hole injection layer (HIL), a hole transporting layer (HIL), and a light emitting layer, which are sequentially stacked between the first electrode 12 and the second electrode 16, Layer structure of an HTL, an emitting material layer (EML), an electron transporting layer (ETL), and an electron injection layer (EIL).

The organic light emitting diode device may be divided into a bottom emission type and a top emission type depending on a light transmission direction. That is, when the first electrode 12 is transparent and the second electrode 16 is opaque, the light of the organic light emitting layer 14 is displayed through the first electrode 12, emission of light from the organic light emitting layer 14 is displayed through the second electrode 16 when the first electrode 12 is opaque and the second electrode 16 is transparent or translucent , Which is referred to as a top emission method.

In the case of the bottom emission type, since the light is transmitted through the first substrate 10 on which the switching thin film transistor and the driving thin film transistor are formed, the organic light emitting diode device of the top emission type is advantageous in terms of the aperture ratio.

On the other hand, the organic light emitting layer 14 of the light emitting diode Del is very vulnerable to external moisture, and a configuration for protecting the organic light emitting layer 14 from external moisture is required.

The present invention aims to prevent the organic light emitting layer from being damaged by external moisture in an organic light emitting diode device of a top emission type having an advantage in terms of an aperture ratio.

In addition, a protection layer for preventing damage to the organic light emitting layer is formed while preventing an efficiency deterioration thereof.

Further, in the flexible organic light emitting diode device, it is intended to prevent the efficiency from lowering.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a first substrate including a plurality of sub-pixel regions; A first electrode opposed to the plurality of sub pixel areas and disposed on each of the plurality of sub pixel areas and a second electrode facing the first electrode and covering the entirety of the plurality of sub pixel areas and made of a silver / magnesium alloy having a silver content greater than a magnesium content, And an organic light emitting layer disposed between the first electrode and the second electrode in each of the plurality of sub pixel regions; A first protective layer formed on the light emitting diode and covering the entire first substrate, the first protective layer being made of a first inorganic insulating material; And a second substrate disposed on the first passivation layer, wherein a refractive index of the first inorganic insulating material is greater than a refractive index of the second substrate.

And the ratio of the content of silver to the content of magnesium is 3 to 9: 1.

Wherein each of the first and second substrates is made of glass.

Wherein the first passivation layer is formed of any one of SiO2, SiNx, SiON, ZrO, HfO, TaO, RuO, ZnO, WO, CoO and ZnS.

Each of the first and second substrates is made of plastic.

And the first passivation layer is made of ZnS.

A second protective layer formed between the second substrate and the first protective layer and made of silicon nitride and an adhesive layer between the second substrate and the second protective layer.

A gate line and a data line which are located on the first substrate and intersect with each other to define the plurality of sub pixel regions; A switching thin film transistor located in each of the plurality of sub pixel regions and connected to the gate wiring and the data wiring; A driving thin film transistor connected to the switching thin film transistor and the first electrode; And a power wiring connected to the driving thin film transistor.

In the present invention, it is possible to protect the organic light emitting layer from external moisture in the organic light emitting diode device of the top emission type, thereby preventing deterioration of device characteristics due to damage of the organic light emitting layer.

At this time, the protective layer for protecting the organic light emitting layer is made of an inorganic insulating material whose refractive index is larger than that of the glass substrate, and the second electrode as the cathode is formed of a silver-magnesium alloy (Ag: Mg) It is possible to prevent light loss due to the layer.

In addition, in the organic light emitting diode device having flexible characteristics, by forming the inorganic material layer having a high refractive index, it is possible to prevent the decrease in efficiency due to the flexible characteristics.

Therefore, the organic light emitting diode device has an effect of providing a highly efficient organic light emitting diode device while preventing damage to the organic light emitting layer.

1 is a view showing one sub-pixel region of a conventional organic light emitting diode device.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting diode.
3 is a schematic cross-sectional view of an organic light emitting diode device according to a first embodiment of the present invention.
4 is a graph showing a refractive index for each wavelength according to a cathode component;
5 is a graph showing the relative permeability after passing through the protective layer according to the cathode component.
6 is a schematic cross-sectional view of an organic light emitting diode device according to a second embodiment of the present invention.
7 is a graph showing an electroluminescence spectrum of a conventional organic light emitting diode device.
FIG. 8 is a graph showing an electroluminescence spectrum of an organic light emitting diode device according to a second embodiment of the present invention. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

3 is a schematic cross-sectional view of an organic light emitting diode device according to a first embodiment of the present invention.

The organic light emitting diode device 100 includes a first substrate 101, a light emitting diode Del located on the first substrate 101, a protective layer (not shown) covering the light emitting diode Del, 150 and a second substrate 160 covering the protective layer 150. [ The first and second substrates 101 and 160 are all glass substrates. The organic light emitting diode device 100 of the present invention is a top emission type in which light emitted from the light emitting diode Del passes through the passivation layer 150 and the second substrate 160.

Although not shown, on the first substrate 101, a gate wiring and a data wiring cross each other to define a sub-pixel region SP, and a power wiring is formed in parallel to the gate wiring or the data wiring. In addition, a switching thin film transistor connected to the gate wiring and the data wiring is located in each of the sub-pixel areas SP.

The driving thin film transistor Td is connected to each of the switching thin film transistor and the power wiring to control a voltage applied to the light emitting diode. Although not explicitly shown, the driving thin film transistor Td may include a gate electrode, a semiconductor layer, and a source electrode and a drain electrode.

An insulating material layer 110 is formed to cover the driving thin film transistor Td and a light emitting diode Del is disposed on the insulating material layer 110.

The insulating material layer 110 may include a contact hole exposing a drain electrode of the thin film transistor Td and the light emitting diode Del may be connected to the driving thin film transistor Td through the contact hole. do.

That is, the light emitting diode Del may include a first electrode 120, a second electrode 140 facing the first electrode 120, and an organic emission layer 140 between the first and second electrodes 120 and 140. [ The first electrode 120 is connected to the driving thin film transistor Td through the contact hole on the insulating material layer 110.

The first electrode 120 is formed for each sub-pixel region SP and is made of a conductive material having a large work function value to serve as an anode. For example, the first electrode 120 may include a layer of a transparent conductive material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) .

Since the organic light emitting diode device of the present invention is a top emission type, the first electrode 120 includes a reflective material layer. That is, a reflective layer may be formed on or under the first electrode 120, or the first electrode 120 may include a reflective material layer together with a transparent conductive material layer. In the latter case, for example, it may be a multilayer structure including a transparent conductive material layer made of ITO or IZO and a silver alloy layer, and the silver alloy layer may be a silver-palladium-copper alloy layer have.

The organic light emitting layer 130 is formed on the first electrode 120 for each of the sub pixel areas SP and the organic light emitting layer 130 is formed on the red, green, and blue organic light emitting layers 130 ). A bank 115 is formed between the sub-pixel regions SP and the first electrode 120 and the organic light emitting layer 130 are separated by the sub-pixel region SP with the bank 115 as a boundary .

In order to improve the luminous efficiency, the organic light emitting layer 130 may have a multi-layer structure. For example, the organic light emitting layer 130 may include a hole injection layer (HIL), a hole transporting layer (HIL), and a light emitting layer, which are sequentially stacked between the first electrode 120 and the second electrode 140. (HTL), an emitting material layer (EML), an electron transporting layer (ETL), and an electron injection layer (EIL).

The second electrode 140 is located on the organic light emitting layer 130 in correspondence with the entire plurality of sub-pixel regions SP. The second electrode 140 is made of a conductive material having a small work function value to serve as a cathode. For example, the second electrode 140 may be formed of a silver-magnesium alloy (Ag: Mg).

The passivation layer 150 completely covers the light emitting diodes Del located in the plurality of sub pixel areas SP. The organic light emitting layer 130 of the light emitting diode Del is easily damaged by external moisture, thereby degrading device characteristics and shortening the lifetime. In the present invention, the protective layer 150 covering the light emitting diode (Del) is provided to prevent the organic light emitting layer 130 from being damaged by external moisture.

The protective layer 150 is made of an inorganic insulating material and has a thickness of about 1.5 to 3 mu m. Therefore, penetration of moisture or the like outside can be sufficiently prevented by the light emitting diode (Del).

A capping layer (not shown) may be formed between the second electrode 140 and the passivation layer 150 to improve the light extracting effect.

A feature of the present invention is that the second electrode 140 is made of a silver-magnesium alloy, and the silver content is larger than the magnesium content. For example, the content ratio of silver to magnesium may be about 3 to 9: 1. The passivation layer 150 may be formed of a silicon compound such as SiO2, SiNx, or SiON or a transition metal compound such as ZrO, HfO, TaO, RuO, ZnO, WO, CoO, or ZnS. The protective layer 150 made of the above material is made of a material having a refractive index larger than that of the material of the second substrate 160.

By including the second electrode 140 and the protective layer 150 as described above, the present invention can protect the organic light emitting layer 130 to improve device characteristics and lifetime, and suppress light loss due to the protective layer 150 have.

That is, if the protective layer 150 is formed to prevent the organic light emitting layer 130 from being damaged, light loss due to the protective layer 150 occurs, thereby reducing the efficiency of the device. However, as in the present invention, the protective layer 150 is formed of an inorganic insulating material larger than the second substrate 160, which is a glass substrate, and the second electrode 140, which is a cathode, is formed of a silver- , The organic light emitting layer 130 can be protected and light loss can be prevented.

Table 1 shows the change in efficiency of the case where the cathode in which magnesium is the main component and the protective layer of the inorganic insulating material are combined (Comparative Example 1 and Comparative Example 2), and the case where the cathode, which is the main component, (Experimental Example 1 and Experimental Example 2) are shown in Table 2. < tb > < TABLE >

Reference element Device with protective layer R G B R G B Comparative Example 1 29.9 48.2 4.5 27.9 42.7 3.7 Comparative Example 2 29.6 47.6 4.4 27.0 42.3 3.5 Average 29.8 47.9 4.5 27.5
(-8%) 42.5
(-11%) 3.6
(-20%)

Reference element Device with protective layer R G B R G B Experimental Example 1 41.9 61.4 6.0 49.3 63.9 5.9 Experimental Example 2 42.3 61.9 6.0 49.5 63.4 6.0 Average 42.1 61.7 6.0 49.4
(+ 17%) 63.7
(+ 3%) 6.0
(-)

The reference device in Table 1 and Table 2 is a case in which an air layer is present between the light emitting diode and the upper substrate as shown in FIG. 2, and Comparative Example 1 and Comparative Example 2 are cases where the silver-magnesium alloy (magnesium: silver = 9: 1). In Experimental Examples 1 and 2, the second electrode is formed of a silver-magnesium alloy (silver: magnesium = 9: 1) as a main component. In Comparative Example 1, Comparative Example 2, Experimental Example 1 and Experimental Example 2, the protective layer was formed to a thickness of 2 탆 using silicon nitride (SiNx), and the thickness of the second electrode was 150 Å.

As shown in Table 1, in the case of using a protective layer made of an inorganic insulating material, in Comparative Examples 1 and 2 in which magnesium is a main component, efficiency in all wavelength ranges of red (R), green (G) and blue (B) . However, as shown in Table 2, the transmittance of blue (B) did not change and the efficiencies of red (R) and green (G) increased in Experimental Examples 1 and 2 where silver was the main component.

As shown in FIG. 4, which is a graph showing a refractive index for each wavelength band according to the cathode component, the cathode that is a main component of magnesium and the cathode that is a main component of silver have a similar refractive index in a short wavelength region. In a long wavelength region, Is larger than the refractive index of the cathode which is the main component.

Referring to FIG. 5, which is a graph showing the relative transmittance after passing through the protective layer according to the cathode component, when a protective layer of an inorganic insulating material is stacked on a cathode that is a main component of silver, When passing through the cathode which is the main component, the permeability is larger than when the cathode passes through the magnesium-based cathode.

This is because the refractive index of the protective layer made of an inorganic insulating material is larger than the refractive indices of the cathode and the second substrate in the laminated structure of the protective layer made of the cathode and the inorganic insulating material and the second substrate, Seems to be.

That is, in Comparative Example 1 and Comparative Example 2 using a magnesium-based cathode, the transmittance was lowered by the protective layer made of an inorganic insulating material, whereas in Experimental Example 1 and Experimental Example 2 using the cathode which is a silver- Even if a protective layer made of an insulating material is used, the transmittance does not decrease due to the optical effect due to the difference in refractive index. Therefore, it is possible to prevent a decrease in efficiency of the organic light emitting diode device while forming a protective layer for preventing damage to the organic light emitting layer of the organic light emitting diode device, thereby improving the efficiency and lifetime of the organic light emitting diode device at the same time.

6 is a schematic cross-sectional view of an organic light emitting diode device according to a second embodiment of the present invention.

As shown in the figure, the organic light emitting diode device 200 includes a first substrate 201, a light emitting diode (Del) located on the first substrate 201, and a light emitting diode (LED) A second substrate 260 covering the first protective layer 250 and the second protective layer 255 and the second protective layer 255 and an adhesive layer 257 for attaching the second substrate 260 . The first and second substrates 201 and 260 are plastic substrates, and the organic light emitting diode device 200 has a flexible characteristic. The organic light emitting diode device 200 of the present invention is a top emission type in which light emitted from the light emitting diode Del passes through the first and second passivation layers 250 and 255 and the second substrate 260.

Although not shown, on the first substrate 201, a gate wiring and a data wiring cross each other to define a sub-pixel region SP, and a power wiring is formed in parallel to the gate wiring or the data wiring. In addition, a switching thin film transistor connected to the gate wiring and the data wiring is located in each of the sub-pixel areas SP.

The driving thin film transistor Td is connected to each of the switching thin film transistor and the power wiring to control a voltage applied to the light emitting diode. Although not explicitly shown, the driving thin film transistor Td may include a gate electrode, a semiconductor layer, and a source electrode and a drain electrode.

An insulating material layer 210 is formed to cover the driving thin film transistor Td and a light emitting diode Del is disposed on the insulating material layer 210.

The insulating material layer 210 may include a contact hole exposing a drain electrode of the thin film transistor Td and the light emitting diode Del may be connected to the driving thin film transistor Td through the contact hole. do.

That is, the light emitting diode Del may include a first electrode 220, a second electrode 240 facing the first electrode 220, and an organic emission layer 240 between the first and second electrodes 220 and 240. [ The first electrode 220 is connected to the driving thin film transistor Td through the contact hole on the insulating material layer 210.

The first electrode 220 is formed for each sub-pixel region SP and is made of a conductive material having a large work function value to serve as an anode. For example, the first electrode 220 may include a layer of a transparent conductive material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) .

Since the organic light emitting diode device of the present invention is a top emission type, the first electrode 220 includes a reflective material layer. That is, a reflective layer may be formed on or under the first electrode 220, or the first electrode 220 may include a reflective material layer together with a transparent conductive material layer. In the latter case, for example, it may be a multilayer structure including a transparent conductive material layer made of ITO or IZO and a silver alloy layer, and the silver alloy layer may be a silver-palladium-copper alloy layer have.

The organic light emitting layer 230 is formed on the first electrode 220 for each of the sub pixel areas SP and the organic light emitting layer 230 is formed on the organic light emitting layer 230 of red, ). A bank 215 is formed between the sub-pixel regions SP and the first electrode 220 and the organic light emitting layer 230 are separated by the sub-pixel regions SP with the bank 215 as a boundary .

In order to improve the luminous efficiency, the organic light emitting layer 230 may have a multi-layer structure. For example, the organic light emitting layer 130 may include a hole injection layer (HIL), a hole transporting layer (HIL), and a light emitting layer, which are sequentially stacked between the first electrode 220 and the second electrode 240. (HTL), an emitting material layer (EML), an electron transporting layer (ETL), and an electron injection layer (EIL).

The second electrode 240 is located on the organic light emitting layer 230 corresponding to the plurality of sub-pixel regions SP. The second electrode 240 is made of a conductive material having a small work function value to serve as a cathode. For example, the second electrode 240 may be formed of a silver-magnesium alloy (Ag: Mg).

The organic light emitting diode device 200 according to the second embodiment of the present invention is of a flexible type and requires an adhesive layer 257 to attach the second substrate 260 which is a plastic substrate. At this time, damage of the light emitting diode (Del) may be caused by the solvent of the adhesive layer (257), and a second passivation layer (255) is formed to prevent this. That is, a second protective layer 255 made of silicon nitride (SiNx) is formed under the adhesive layer 257 to block the solvent of the adhesive layer 257. At this time, in order to sufficiently block the solvent, the second passivation layer 255 may have a thickness of about 1 탆 or more.

In this manner, the second protective layer 255, the adhesive layer 257 and the second substrate 260 are stacked on the light-emitting diode Del in comparison with a non-flexible structure using a glass substrate. Referring to FIG. 7, which is a graph showing an electroluminescent spectrum, the mircocavity characteristic in the device is changed by the lamination structure of the second passivation layer 255 and the adhesive layer 257, A peak is formed. That is, the field emission spectrum is shifted from the long wavelength region to the short wavelength region, and the efficiency is affected by the visual sensitivity.

The characteristics of the organic light emitting diode device (non-flexible OLED, Comparative Example 1) and the flexible organic light emitting diode device (Flexible OLED, Comparative Example 2) having no flexible characteristic by using the glass substrate are shown in Table 3 below.

Voltage [V] Efficiency [cd / A] Color coordinates (Bx) Color coordinates (By) Comparative Example 1 3.8 4.8 0.137 0.055 Comparative Example 2 3.9 3.5 0.137 0.055

As shown in Table 3, the comparative examples 1 and 2 show similar characteristics in terms of the color coordinates and the driving voltage. However, the efficiency (Cd / A) of the flexible organic light emitting diode device is changed by changing the micro- Which is about 27% lower than that of the previous study. That is, the flexible organic light emitting diode device causes a decrease in efficiency.

In order to overcome such a disadvantage, in the present invention, a first passivation layer 250 having a high refractive index is formed between the second passivation layer 255 and the light emitting diode Del. That is, the first protective layer 250 is made of an inorganic insulating material having a refractive index larger than that of the first protective layer 255 and the second substrate 260. For example, the first passivation layer 250 may be formed of zinc sulfide (ZnS) having a refractive index of about 2.4.

The first passivation layer 250 completely covers the light emitting diode Del to prevent the light emitting diode Del from being damaged by external moisture, and the second passivation layer 255, the adhesive layer 257 And the second substrate 260 made of plastic, even if the second substrate 260 is used.

Particularly, such an effect requires that the second electrode 240 is made of a silver-magnesium alloy, and that the content of silver is larger than the content of the magnesium. For example, the content ratio of silver to magnesium may be about 3 to 9: 1.

The second electrode 240 and the first passivation layer 250 may be used to protect the organic light emitting layer 230 to improve the device characteristics and lifetime of the organic light emitting device. Can be suppressed.

That is, the second protective layer 255 is formed to prevent the damage of the light emitting diode Del, particularly the organic light emitting layer 230, due to the solvent in the adhesive layer 257 formed for attaching the second substrate 260 made of plastic The efficiency of the device is lowered due to the change of the microcavity structure due to the second protective layer 255 and the adhesive layer 257. However, as in the present invention, the first passivation layer 250 having a high refractive index is formed between the second passivation layer 255 and the light emitting diode (Del), and the second electrode 240, which is a cathode, -Magnesium alloy to protect the light emitting diode (Del) in the flexible organic light emitting diode device (200), thereby improving the device characteristics such as lifetime and preventing a decrease in efficiency due to light loss.

As described above, in comparison with a non-flexible structure using a glass substrate, a light-emitting diode (Del) including a second electrode 240 made of a silver-magnesium alloy, which is a main component of silver, A second protective layer 255 made of an inorganic insulating material having a low refractive index, an adhesive layer 257, and a second substrate 260 are stacked on the first substrate 250, Referring to FIG. 8, which is a graph showing an electroluminescent spectrum in the case of the flexible structure according to the present invention, the electroluminescence spectrum is shifted to the long wavelength region by the re-change of the mircocavity characteristic in the device, do.

(Non-flexible OLED, Comparative Example 3) using a cathode that is a magnesium-based material and having a flexible characteristic by using a glass substrate and an organic light-emitting diode (OLED) device having a flexible property and a cathode as a main component (Experimental Example), the efficiency (Cd / A) of the flexible organic light emitting diode device according to the second embodiment of the present invention is increased by about 8%. That is, although the structure of the adhesive layer and the second protective layer is added for the flexible property, the efficiency is increased due to the optical effect of the cathode, which is the main component of silver, and the first protective layer of the inorganic insulating material having a high refractive index.

Voltage [V] Efficiency [cd / A] Color coordinates (Bx) Color coordinates (By) Comparative Example 3 4.1 6.5 0.137 0.055 Experimental Example 3.9 7.0 0.137 0.055

As described above, in the second embodiment of the present invention, a plastic substrate and an adhesive layer for attaching the plastic substrate are provided to provide a flexible organic light emitting diode device. In order to prevent the organic light emitting diode from being damaged by the adhesive layer, The second protective layer made of an insulating material is positioned below the adhesive layer.

In this flexible organic light emitting diode device, the second electrode of the light emitting diode, that is, the cathode, is formed of a silver-magnesium alloy as a main component and a first protective layer having a high refractive index is formed on the second electrode , Thereby preventing a reduction in the efficiency of the device.

That is, the organic light emitting diode device according to the second embodiment of the present invention has a flexible characteristic by protecting the light emitting diode with the first and second protective layers and using the plastic substrate on the first and second substrates, The cathode may be formed of a silver-magnesium alloy, and the first protective layer on the cathode may be formed of an inorganic insulating material having a high refractive index.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

100, 200: organic light emitting diode device 120, 220: first electrode
130, 230: organic light emitting layer 140, 240: second electrode
150, 250: (first) protection layer 255: second protection layer
Del: Light emitting diode

Claims (8)

A first substrate including a plurality of sub pixel regions;
A first electrode opposed to the plurality of sub pixel areas and disposed on each of the plurality of sub pixel areas and a second electrode facing the first electrode and covering the entirety of the plurality of sub pixel areas and made of a silver / magnesium alloy having a silver content greater than a magnesium content, And an organic light emitting layer disposed between the first electrode and the second electrode in each of the plurality of sub pixel regions;
A first protective layer formed on the light emitting diode and covering the entire first substrate, the first protective layer being made of a first inorganic insulating material;
A second substrate positioned on the first passivation layer;
A second protective layer positioned between the second substrate and the first protective layer;
And an adhesive layer positioned between the second substrate and the second protective layer,
Wherein the first protective layer has a larger refractive index than the second protective layer and the second substrate,
Wherein the second passivation layer is in contact with the first passivation layer and the adhesive layer.
The method according to claim 1,
Wherein the content of silver and the content of magnesium are 3 to 9: 1.
The method according to claim 1,
Wherein each of the first and second substrates is made of glass.
The method of claim 3,
Wherein the second passivation layer is made of any one of SiO2, SiNx, SiON, ZrO, HfO, TaO, RuO, ZnO, WO, and CoO.
The method according to claim 1,
Wherein each of the first and second substrates is made of plastic.
6. The method of claim 5,
Wherein the first passivation layer is made of ZnS.


delete The method according to claim 1,
A gate line and a data line which are located on the first substrate and intersect with each other to define the plurality of sub pixel regions;
A switching thin film transistor located in each of the plurality of sub pixel regions and connected to the gate wiring and the data wiring;
A driving thin film transistor connected to the switching thin film transistor and the first electrode;
And a power wiring connected to the driving thin film transistor.

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